9.4.4 Basic query monitoring

Basic monitoring of a query statement is easy with
PECL/mysqlnd_uh. Combined with
debug_print_backtrace
it can become a powerful tool, for example, to find the origin
of certain statement. This may be desired when searching for
slow queries but also after database refactoring to find code
still accessing deprecated databases or tables. The latter may
be a complicated matter to do otherwise, especially if the
application uses auto-generated queries.

For basic query monitoring you should install a connection and a
prepared statement proxy. The connection proxy should subclass
MysqlndUhConnection::query.
All database queries not using native prepared statements will
call this method. In the example the query
function is invoked by a PDO call. By default,
PDO_MySQL is using prepared statement
emulation.

All native prepared statements are prepared with the
prepare method of mysqlnd
exported through
MysqlndUhPreparedStatement::prepare.
Subclass MysqlndUhPreparedStatement and
overwrite prepare for native prepared
statement monitoring.